The study examines whether elementary school students in Taiwan who had received Montessori education achieved significantly higher scores on tests of language arts, math, and social studies than students who attended non-Montessori elementary programs. One hundred ninety six children in first, second, and third grade participated in the study. Children's scores were measured by Elementary School Language Ability Achievement Test (ESLAAT), Elementary School Math Ability Achievement Test (ESMAAT), and Social Studies Ability Achievement Test (SSAAT). One-way multivariate analysis of variance (MANOVA) showed that students who had Montessori experience had a significantly higher score in language arts in all three grade levels. In math, first grade students scored higher but not second and third grade students. However, in social studies, students who had received Montessori education did not score significantly higher than the non-Montessori students. There was also no significant difference between the number of years spent in Montessori programs and students' language arts, math, and social studies test scores in first, second, and third grade.